Positive scuttling buoy



y 4, 1968 J. L. BOSCOV 3,382,514

POSITIVE SCUTTLING BUOY Filed Oct. 19. 1966 lNVE/V 70/? JOSEPH L. 80$COV ATTOR/V VS.

United States Patent 3,382,514 POSITIVE SCUTTLING BUOY Joseph L. Boscov, 900 Brighton Ave, Reading, Pa. 19608 Filed Oct. 19, 1966, Ser. No. 587,737 9 Claims. (Cl. 9--8) ABSTRACT OF THE DISCLGSURE Positive scuttling of devices such as buoys is obtained by providing an outer air-permeable shape-defining envelope and an internal balloon made of resilient elastic material. On inflation with flotation fluid, the balloon expands to fill the envelope, storing energy in it tensioned material, and the device is rendered buoyant. When, after a predetermined interval, the balloon is 'vented, its contraction and consequent release of stored energy cause positive expulsion of flotation fluid, so that buoyancy is lost.

This invention relates to positive scuttling buoy which float on a supporting liquid for a predetermined time and then sink. More particularly, it relates to inflatable disposable buoys which find wide military and civilian applications. These include, for example, submarine detection, underwater sound ranging and marine seismic prospecting.

Sevenal types of inflatable scuttling buoy are described in the prior art which are suitable to be dropped from an airplane in a compact, deflated form. Upon hitting the water, automatic inflation means go into operation to cause the buoy to assume its inflated flotation contour. After a predetermined time, during which the buoy has performed its stated function (e.g., the support of an electronic instrument package) the buoy, at least in theory, scuttles itself. The reason for such scut-tiing is to make the instrument package unavailable to unauthorized personnel and to clear the surface of the water so as to leave no trace of the buoys presence.

The self-scuttling devices of the past have, on many occasions not operate-d as intended to fully sink the buoy. Most of these devices involved a time-delayed means for permitting water to enter the buoy and physically displace the flotation fiuid (e.g., gas) contained therein. Sometimes, however, this displacement was not complete and a trapped pocket of gas remained which could not be displaced by the liquid. This remaining gas pocket often proved large enough to prevent the buoy from sinking.

The existence of this problem was recognized and a solution thereto presented in US. Patent No. 3,081,466 which was assigned on its face to the Secretary of the Navy. The general approach taken in that patent is to vent the top of a constant volume buoy to the atmosphere while allowing liquid to enter the bottom so that liquid is free to rise up in the buoy without creating a trapped pocket of gas. Naturally, this involved elements of structure which would not otherwise have been necessary.

This invention takes a totally different approach to the solution of the same problem. It achieves a positive mechanical expulsion of flotation fluid from the buoy as distinguished from the mere displacement of the gas by the supporting liquid. 7

Accordingly, it is an object of the invention to provide an inflatable buoy, which is scuttled after a predetermined time, by the positive expulsion of flotation fluid into the liquid on which the buoy floats.

It is a further object of the invention to provide a flotation device which includes an outer envelope, and

ice

an inner resilient balloon which, when inflated with a flotation fluid, renders the device buoyant and which, when deflated, positively contracts to a size insufiicient to hold enough flotation fluid to keep the device buoyant.

Another object of the invention is to provide a buoy, suitable for use in air-drop applications, which will be positively self-scuttling after a predetermined time without requiring a plurality of moving parts or expensive components in order to insure such operation.

An additional object of the invention is to provide a device of the character described wherein the inflation pressure of the flotation fluid is used to store energy in a resilient member and where, during deflation, this energy is released to cause positive expulsion of the fluid.

It is also an object of the invention to provide a positive scuttl-ing device for flotation on a supporting liquid which is rugged in construction, easily and inexepensively manufactured, highly reliable and eflicient in use and which, while representing an improvement over the prior art devices, achieves the improvement with a simplification in structure.

These and other related objects of the invention will be apparent to those skilled in the art from a consideration of the description which follows.

The various features and details of construction of the invention are fully set forth herein with reference to the accompanying drawing, in which like reference numerals designate like parts and in which:

FIGURE 1 is a fragmentary perspective view, partly cut away, showing a buoy of the invention in its inflated buoyant condition on a body of supporting liquid.

FIGURE 2 is a fragmentary perspective view, partly in section, showing the buoy of FIGURE 1 as it sinks in its deflated non-buoyant condition.

FIGURE 3 is an enlarged fragmentary perspective view, partly in section, showing detail of construction of portion of the buoy of FIGURE 1.

Briefly stated, the embodiment of the positive scuttling devices of the invention disclosed herein comprises an instrument package housing A which is adapted to be rendered buoyant by an attached resilient balloon B. The balloon is protected by a contour-defining outer envelope C which may also be attached to housing A. Balloon B is inflated by inflation means D, preferably located in housing A. Time-delayed vent means E, operating sequentially after the inflation means D, cause postitive scuttling of the total device.

Instrument package housing A may be of any shape or size, dependent upon its function. Its center of gravity, shape, and weight all determine the buoyancy required to keep it afloat and therefore determine the size and other parameters of balloon B. As shown in FIGURE 1, housing A may be generally cylindrical and include walls 10 and a top 11. Mounted on top 11 is a hollow neck member, generally 12, which is provided with a radially extending bottom flange 13. Flange 13 is utilized to attach the neck 12 to the top 11. The contents of the instrument package may include a radio transmitter, in which case a flexible transmitting antenna 14 is provided which extends upwardly through top 11 and neck 12. Where the antenna penetrates top 11, appropriate means may be utilized for making the point of penetration gas-tight (e.g., a sealant, a rubber grommet, etc.).

Resilient balloon B may include an open mouth 20 and a closed end 21. Particular applications may require further modifications in construction. Thus, for instance, in the embodiment shown, an internal hook 22 is cemented to end 21 and the terminal end of the antenna 14 is at tached thereto.

Balloon B is made of any resilient material, impermeable to flotation fluids such as gases like air, carbon dioxide and the like. Its essential characteristic, however,

is a resilient elasticity which will allow it to be stretched and tensionedwhen filled with, or inflated by, the flota- I tionfiuid until it fills out and assumes the contour of envelope C. In fully inflated condition (i.e., as shown in FIGURE 1) the energy of inflation is stored in the bal loons walls in the form of tension and, once means are her, silicone rubber and those plastic films which have.

an elastic memory.

Balloon B is attached to package A by fitting mouth 20 over neck 12.. Preferably it should be cemented in place although, if desired, awide variety of clamping means may be utilized. It should be realized that the elasticity of the material from which the balloon is made contributes to the retention. '7

The shape of the balloon and the visible appearance of the device, when floating, is a function of the contour of outer envelope C. Thislfenvelope may be made of any flexible, gas perrneable material such as canvas, cloth,

plastic-derived fabrics (eg, those derived from lOngchain polymeric amides, polyesters, etc.) or similar materials which, whilerugged enough tosurvive physical handling including an air drop, are porous enough to permit passage of air. Theenvelope is preferably formed with an open mouth 30,; an intermediate bulbous section extends upwardly into the, atmosphere. The specific shape of the envelope is a function of the character of the instrument packageA and the desired center of gravity of the device when in flotation condition. The envelope, in and of itself, need have no buoyancy and should be of a it material which can be readily folded or crumpled, such as the materials described above, so that as originally packaged for dropping from an airplane itoccupies a minimum volume. Coloration and contour may be selected to either increase or decrease visibility dependent upon the application involved. The use of radio wave reflecting mitter (not shown),.the output of which is coupled to resilient antenna 14 are also included. The electronic con- .31and,.for an application involving radio transmission or reception, a frusto-conical terminal portion.32 which 3 fact, in certain applications, where the device functions merely as a buoy, theinflation means could constitute the totalcontents of the housing. In this particular embodiment, however, instruments including a radio transtents of the housing form no part ofthe instant invention.

The inflation means includes a cartridge 40 containing compressed .inflationfluid. This may be, for instance, a.

cartridge of compressed gas such as, for example, carbon dioxideor compressedair. Other materialssuch as freon which, upon release of pressure, undergoa change in state are also suitable as long as the fluid entering the balloon.

has a density. less thanthat of the supporting liquid. Re-

i gardle ss. of the specific contents of cartridge 40, the .ob-

jective is to store therein a flotation fluid which can inflate balloon B and thus render the device buoyant. Linked to cartridge .40 is an automatic valve 41. These valves, which are well known in the prior art and are per- Q when dropped from an airplane, to a chemical reaction caused by the action of salt water, or to timer-initiated detonation of a squib. Until valve41 opens, balloon, B

remains uninfiated.,When the valve does open, inflation fluid travels under pressure through conduit 42 to the interior of the balloon.

When the balloon is inflated the device rides upon a body of supporting liquid 43 as shown in FIGURE 1.

.The liquid is generally water, most often sea water. For

such applications carbon dioxide has been found to be a most suitable flotation timid and inflation pressures within the balloon when it is used are onthe order of four to eight p.s.i,g. This pressure is suflicient to cause the balloon to fill the totality of envelope C, and to result in the erection of flexible antenna 14 which, as theunit is packaged prior to inflation, may be conveniently coiled up within neck 12.

Vent means E are time-delayed and operate only after the inflation, described above, has occurred. These means include a passageway 45 which extends from the interior of balloon B, seriatim, through neck 12, mouth 20, and

mouth 30 to the exterior of the assembly. The passageway is blocked by a plug 46 made of material which is slowly soluble in supporting liquid 43 (e.g., a salt composition).

Alternatively, the plug may be metallic and may dissolve due to the electrolytic action caused by battery leakage onto it. Once the plug has dissolved the passageway is open.

Were one dealing with the prior art buoys, where the 1 container for flotation fluid had a substantially constant volume, the only pressure gradient which would ever cause displacemento-f flotation fluidby supporting liquid would be the difference between the fluid pressure inside the buoy and the static head of supporting liquid above tension and cause it to return to a small size.

Referring to the figures, it will be observed in FIGURE 2 that the device is sinking because balloon B has substantially regained its initial dimensions and does not contain suflicient flotation fluid to make the device buoyant. Further, envelope C, because it is made of airit permeable material cannot serve to retain fluid under pressure and add buoyancy. In some embodiments of the invention, particularly those where the housing A contains instrumentation and voids it may be desirable to provide an additional plug 45 in wall 10 to flood the housing. In designs where inflation fluid is permitted to enter the housing as well as the balloon, a plug in the wall of the housing would serve as a vent for both.

Although the invention has been. described in considerable detail, such description is intended to be illustrative rather than limiting since the invention may be variously embodied. Consequently, its extent is to be determined by the appended claims.

Having described by invention, I claim:

1. A positive scuttling device for flotation on a supporting liquid comprising:

(a) aflexible, air-permeable, shape-defining outer en velope;

(b) a balloon rnade of resilient elastic material-located within said envelope which, as it is inflated with a quantity of flotation fluid suflicient to render said device buoyant, expands from its original size to fill said envelope and assume its configuration, said resilient elastic material being tensioned during inflation to store energy and the balloon, when subsequent'deflation occurs, contracting to a size insuflicient tohold enough flotation fluid to keen said device buoyant, the stored energy in said tensioned material being utilized to positively expel flotation fluid from the balloon as it contracts, and

(c) inflation means supported by said device and operatively associated with said balloon for inflating it with a flotation fluid, and

(d) time delayed vent means, operatively associated with said balloon and operating sequentially at a predetermined interval after said inflation means, to establish an open passage between the interior of said balloon and the supporting liquid on which said device floats,

the ensuing expulsion of flotation fluid from the interior of said balloon continuing until said balloon ceases to contract.

2. The device of claim 1 wherein said outer envelope includes a bulbous lower section extending below the level of the supporting liquid and an upper section extending into the atmosphere.

3. The device of claim 1 wherein said time delayed vent means comprises a plug of material which is soluble in the supporting liquid, said plug being located in an area in contact with the supporting liquid when the device is floating and said flotation fluid being expelled into the supporting liquid when said vent means becomes opera-tive.

4. The device of claim -1 wherein said envelope has a mouth, said balloon has a mouth and the device further includes a hollow neck member, the mouth of said envelope and the mouth of said balloon being coaxially mounted on said neck.

5. The device of claim 1 wherein said vent means comprises a passageway, one end of which is in pneumatic communication with the interior of said balloon and the other end of which is exposed to the supporting liquid when said device is floating, and a plug of material sealing said passageway which material is soluble in the supporting liquid.

6. The device of claim 5 wherein said envelope has a mouth, said balloon has a mouth and the device further includes a hollow neck member, the mouth of said envelope and the mouth of said balloon being coaxially mounted on said neck.

7. The device of claim 6 wherein said vent means is located in said neck.

8. The device of claim 4 which further includes an instrument package housing on which said neck is mounted, said housing containing Within it said inflation means.

9. The device of claim 6 which further includes an instrument package housing on which said neck is mounted, said housing containing within it said inflation means.

References Cited UNITED STATES PATENTS 3,081,466 3/ 1963 Bailey 98 3,093,808 6/1963 Tatnall et a1. 98 X 3,131,889 5/19 64 Yost 24431 MILTON BUC-HLE-R, Primary Examiner.

T. MAI OR, Assistant Examiner. 

